Systems, methods, and apparatus for agricultural implement trench depth control and soil monitoring

ABSTRACT

Systems, methods and apparatus are provided for monitoring soil properties including soil moisture and soil temperature during an agricultural input application. Embodiments include a soil moisture sensor and/or a soil temperature sensor mounted to a seed firmer for measuring moisture and temperature in a planting trench. Additionally, systems, methods and apparatus are provided for adjusting depth based on the monitored soil properties.

BACKGROUND

In recent years, the availability of advanced location-specificagricultural application and measurement systems (used in so-called“precision farming” practices) has increased grower interest indetermining spatial variations in soil properties and in varying inputapplication variables (e.g., planting depth) in light of suchvariations. However, the available mechanisms for measuring propertiessuch as temperature are either not effectively locally made throughoutthe field or are not made at the same time as an input (e.g. planting)operation. Moreover, available methods for adjusting depth are noteffectively responsive to changes in soil properties such as depth andtemperature.

Thus there is a need in the art for a method for monitoring soilproperties during an agricultural input application. Moreover, there isa need in the art for adjusting depth based on the monitored soilproperties.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of an embodiment agricultural planter.

FIG. 2 is a side elevation view of an embodiment of a planter row unit.

FIG. 3 schematically illustrates an embodiment of a soil monitoring anddepth control system.

FIG. 4A is a side elevation view of an embodiment of a temperaturesensor and an embodiment of a moisture sensor.

FIG. 4B is a rear elevation view of the temperature sensor and moisturesensor of FIG. 4A.

FIG. 4C is a rear elevation view of another embodiment of a temperaturesensor.

FIG. 5 illustrates an embodiment of a process for controlling trenchdepth based on soil moisture.

FIG. 6 illustrates an embodiment of a process for controlling trenchdepth based on soil temperature.

FIG. 7 illustrates an embodiment of a process for controlling trenchdepth based on soil temperature and soil moisture.

FIG. 8 illustrates another embodiment of a process for controllingtrench depth based on soil temperature and soil moisture.

FIG. 9 illustrates still another embodiment of a process for controllingtrench depth based on soil temperature and soil moisture.

FIG. 10 is a side elevation view of another embodiment of a temperaturesensor.

FIG. 11 illustrates an embodiment of a process for controlling trenchdepth based on soil data.

FIG. 12 illustrates an embodiment of a process for controlling trenchdepth based on soil data and soil temperature.

FIG. 13 illustrates an embodiment of a process for controlling trenchdepth based on weather data.

FIG. 14 illustrates an embodiment of a process for controlling trenchdepth based on weather data and soil temperature.

FIG. 15 illustrates an embodiment of a process for controlling trenchdepth based on soil moisture and soil moisture measurements made at abase station.

FIG. 16 illustrates an embodiment of a process for controlling trenchdepth based on weather data as well as soil moisture and soil moisturemeasurements made at a base station.

FIG. 17 illustrates an embodiment of a planter monitor screen displayinga soil temperature map.

FIG. 18 illustrates an embodiment of a planter monitor screen displayinga soil moisture map.

FIG. 19 illustrates an embodiment of a planter monitor screen displayinga trench depth map.

FIG. 20 illustrates an embodiment of a planter monitor screen displayingsummarized planting data and planting recommendations.

FIG. 21 illustrates an embodiment of a planter monitor screen displayingrow-by-row planting data.

FIG. 22 illustrates an embodiment of a planter monitor screen displayingrow-specific planting data.

FIG. 23 illustrates an embodiment of a planter monitor depth controlsetup screen.

FIG. 24 is a side elevation view of an embodiment of a base station formonitoring and transmitting soil data and weather data.

FIG. 25 is a side elevation of an embodiment of a measurement unit.

FIG. 26 is a side elevation view of an embodiment of a depth sensor.

FIG. 27 illustrates an embodiment of a planter monitor screen forsetting trench depth and displaying soil data.

DESCRIPTION

Depth Control and Soil Monitoring System

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views, FIG. 1illustrates a tractor 5 drawing an agricultural implement, e.g., aplanter 10, comprising a toolbar 14 operatively supporting multiple rowunits 200. An implement monitor 50 preferably including a centralprocessing unit (“CPU”), memory and graphical user interface (“GUI”)(e.g., a touch-screen interface) is preferably located in the cab of thetractor 10. A global positioning system (“GPS”) receiver 52 ispreferably mounted to the tractor 10.

Turing to FIG. 2, an embodiment is illustrated in which the row unit 200is a planter row unit. The row unit 200 is preferably pivotallyconnected to the toolbar 14 by a parallel linkage 216. An actuator 218is preferably disposed to apply lift and/or downforce on the row unit200. A solenoid valve 390 is preferably in fluid communication with theactuator 218 for modifying the lift and/or downforce applied by theactuator. An opening system 234 preferably includes two opening discs244 rollingly mounted to a downwardly-extending shank 254 and disposedto open a v-shaped trench 38 in the soil 40. A pair of gauge wheels 248is pivotally supported by a pair of corresponding gauge wheel arms 260;the height of the gauge wheels 248 relative to the opener discs 244 setsthe depth of the trench 38. A depth adjustment rocker 268 limits theupward travel of the gauge wheel arms 260 and thus the upward travel ofthe gauge wheels 248. A depth adjustment actuator 380 is preferablyconfigured to modify a position of the depth adjustment rocker 268 andthus the height of the gauge wheels 248. The actuator 380 is preferablya linear actuator mounted to the row unit 200 and pivotally coupled toan upper end of the rocker 268. In some embodiments the depth adjustmentactuator 380 comprises a device such as that disclosed in InternationalPatent Application No. PCT/US2012/035585, the disclosure of which ishereby incorporated herein by reference. An encoder 382 is preferablyconfigured to generate a signal related to the linear extension of theactuator 380; it should be appreciated that the linear extension of theactuator 380 is related to the depth of the trench 38 when the gaugewheel arms 260 are in contact with the rocker 268. A downforce sensor392 is preferably configured to generate a signal related to the amountof force imposed by the gauge wheels 248 on the soil 40; in someembodiments the downforce sensor 392 comprises an instrumented pin aboutwhich the rocker 268 is pivotally coupled to the row unit 200, such asthose instrumented pins disclosed in Applicant's co-pending U.S. patentapplication Ser. No. 12/522,253 (Pub. No. US2010/0180695), thedisclosure of which is hereby incorporated herein by reference.

Continuing to refer to FIG. 2, a seed meter 230 such as that disclosedin Applicant's co-pending International Patent Application No.PCT/US2012/030192, the disclosure of which is hereby incorporated hereinby reference, is preferably disposed to deposit seeds 42 from a hopper226 into the trench 38, e.g., through a seed tube 232 disposed to guidethe seeds toward the trench. In some embodiments, the meter is poweredby an electric drive 315 configured to drive a seed disc within the seedmeter. In other embodiments, the drive 315 may comprise a hydraulicdrive configured to drive the seed disc. A seed sensor 305 (e.g., anoptical or electromagnetic seed sensor configured to generate a signalindicating passage of a seed) is preferably mounted to the seed tube 232and disposed to send light or electromagnetic waves across the path ofseeds 42. A closing system 236 including one or more closing wheels ispivotally coupled to the row unit 200 and configured to close the trench38.

Turning to FIG. 3, a depth control and soil monitoring system 300 isschematically illustrated. The monitor 50 is preferably in electricalcommunication with components associated with each row unit 200including the drives 315, the seed sensors 305, the GPS receiver 52, thedownforce sensors 392, the valves 390, the depth adjustment actuator380, the depth actuator encoders 382 (and in some embodiments an actualdepth sensor 385 described later herein), and the solenoid valves 390.In some embodiments, particularly those in which each seed meter 230 isnot driven by an individual drive 315, the monitor 50 is also preferablyin electrical communication with clutches 310 configured to selectivelyoperably couple the seed meter 230 to the drive 315.

Continuing to refer to FIG. 3, the monitor 50 is preferably inelectrical communication with a cellular modem 330 or other componentconfigured to place the monitor 50 in data communication with theInternet, indicated by reference numeral 335. Via the Internetconnection, the monitor 50 preferably receives data from a weather dataserver 340 and a soil data server 345.

Continuing to refer to FIG. 3, the monitor 50 is also preferably inelectrical communication with one or more temperature sensors 360mounted to the planter 10 and configured to generate a signal related tothe temperature of soil being worked by the planter row units 200. Insome embodiments one or more of the temperature sensors 360 comprisethermocouples disposed to engage the soil; in such embodiments thetemperature sensors 360 preferably engage the soil at the bottom of thetrench 38. One such embodiment is illustrated in FIG. 4A, in which aseed firmer 410 is illustrated mounted to the shank 254 by a bracket415. As is known in the art, the seed firmer is preferably designed toresiliently engage the bottom of the trench 38 in order to press seeds42 into the soil before the trench is closed. In the embodiment of FIG.4A, the thermocouple is housed partially inside the firmer 410 andextends slightly from a bottom surface of the firmer in order to engagethe soil such that the temperature sensor 360 generates a signal relatedto the temperature of the soil at the bottom of the trench 38. Asillustrated in the rear elevation view of FIG. 4B, the temperaturesensor 360 preferably extends from the firmer 410 at a transversedistance from the centerline of the firmer such that the temperaturesensor does not contact seeds 42 passing beneath the bottom surface ofthe firmer. In another embodiment illustrated in FIG. 4C, thethermocouple is in contact with a soil-contacting component, e.g., ahollow copper tube 420 housed partially within the firmer 410 andextending therefrom to contact the soil near the bottom of the trench38. In the illustrated embodiment, the tube 420 contacts the soil onboth sides of the trench 38 such that the signal generated by thethermocouple is related to the temperature of the soil at the points ofcontact between the tube 420 and the soil. In other embodiments, one ormore of the temperature sensors 360 may comprise a sensor disposed andconfigured to measure the temperature of the soil without contacting thesoil as disclosed in International Patent Application No.PCT/US2012/035563, the disclosure of which is hereby incorporated hereinin its entirety by reference.

Referring to FIG. 3, the monitor 50 is preferably in electricalcommunication with one or more moisture sensors 350 mounted to theplanter 10 and configured to generate a signal related to thetemperature of soil being worked by the planter row units 200. In someembodiments one or more of the moisture sensors 350 comprise moistureprobes (e.g., sensors configured to measure the electrical conductivityor dielectric permittivity) disposed to engage the soil; in suchembodiments the temperature sensors 360 preferably engage the soil atthe bottom of the trench 38. One such embodiment is illustrated in FIG.4A, in which the moisture sensor 350 is housed partially inside thefirmer 410 and extends slightly from a bottom surface of the firmer inorder to engage the soil such that the moisture sensor 350 generates asignal related to the temperature of the soil at the bottom of thetrench 38. As illustrated in the rear elevation view of FIG. 4B, themoisture sensor 350 preferably extends from the bottom of the firmer 410at a transverse distance from the centerline of the firmer such that themoisture sensor does not contact seeds 42 passing beneath the bottomsurface of the firmer. In another embodiment illustrated in FIG. 10, themoisture sensor 350 includes two co-planar capacitor plates 1020 a and1020 b housed within the firmer 410 which pass adjacent to the bottom ofthe trench without displacing soil at the bottom of the trench. In someembodiments, the firmer 410 includes a region 1030 disposed above thecapacitor plates 1020, the region 1030 having a low permittivity (e.g.,in embodiments in which the region 1030 comprises an air cavity or amaterial having a low permittivity) or a high permittivity (e.g., inembodiments in which the region 1030 contains a material having highpermittivity). In other embodiments, one or more of the moisture sensors350 may comprise a sensor disposed and configured to measure themoisture content of the soil without contacting the soil, e.g., one ormore infrared or near-infra-red sensors disposed to measureelectromagnetic waves generated by one or more emitters (e.g.,light-emitting diodes) and reflected from the soil surface (e.g., thebottom of the trench 38).

Referring to FIG. 3, the monitor 50 is preferably in electricalcommunication with a mobile receiver 54 (e.g., a wireless data receiver)configured to receive data wirelessly (e.g., via a radio transmitter)from a base station 325 located in a field of interest. Turning to FIG.24, the base station 325 preferably includes one or more temperatureprobes 2420, 2422 disposed at multiple depths in the soil in order tomeasure soil temperature at multiple depths. The base station 325preferably includes one or more moisture probes 2430, 2432 disposed atmultiple depths in the soil 40 in order to measure soil moisture atmultiple depths. Each soil and moisture probe is preferably inelectrical communication with a processor 2405. The processor 2405 ispreferably in communication with a wireless transmitter 2415. Theprocessor 2405 is preferably configured to convert signals to a formatsuitable for transmission via the wireless transmitter 2415 and totransmit the resulting formatted signals via the wireless transmitter.The base station 325 preferably includes a digital rain gauge 2410(e.g., an optical, acoustic or weighing-type gauge) and a digital airtemperature sensor 2412, both of which are preferably in electricalcommunication with the processor 2405.

In some embodiments, a temperature and/or moisture measurement may bemade by a measurement unit independent of the row units 200. Anembodiment of a measurement unit 2500 is illustrated in FIG. 25. Themeasurement unit 2500 preferably includes a coulter 2530 disposed toopen a trench 39 in the soil 40; in some embodiments the measurementunit instead includes two angled opening discs disposed to open a morev-shaped trench). The coulter 2530 is preferably rollingly mounted to abracket 2540. The bracket 2540 preferably has sufficient weight to urgethe coulter 2530 into the soil. A gauge wheel 2520 (or pair of gaugewheels) is preferably rollingly mounted to the bracket 2540 and disposedto ride along the surface of the soil, thus limiting the depth of thetrench 39. The depth of the trench 39 is preferably set to a depth ofinterest; e.g., a default trench depth such as 1.75 inches. In someembodiments, the measuring unit 2500 incorporates a depth adjustmentactuator in electrical communication with the monitor 50 and configuredto modify the vertical distance between the mounting points of thecoulter 2530 and the gauge wheel 2520 in order to adjust the trenchdepth. The bracket 2540 is preferably mounted to the toolbar 14 via aparallel arm arrangement 2526 such that the bracket is permitted totranslate vertically with respect to the toolbar. A spring 2518 ispreferably mounted to the parallel arm arrangement in order to urge thecoulter 2530 into the soil 40. A temperature and/or moisture sensor 2550is preferably mounted to the measurement unit 2500 (or in someembodiments the toolbar 14) and configured to measure temperature and/ormoisture of soil in the trench 39. As in the illustrated embodiment, thesensor 2550 may comprise a sensor configured to measure temperatureand/or moisture without contacting the soil such as an infrared sensor.In other embodiments, the sensor 2550 may incorporate sensors configuredto engage the soil at the bottom of the trench 39 similar to thosedescribed herein, e.g., with respect to FIG. 4A.

Depth Adjustment Methods

Various methods disclosed herein in the section titled “Depth ControlMethods” determine desired depths and/or desired depth adjustments. Theactual adjustment of depth to the desired depth may be accomplishedaccording to one of several methods as described in this section.

In a first method, the system 300 sends a command signal to the depthadjustment actuator 380 which corresponds to a desired depth or desireddepth adjustment. The actuator 380 is preferably calibrated such that aset of depths and corresponding command signals are stored in the memoryof the monitor 50.

In a second method, the system 300 sends a command signal to the depthadjustment actuator 380 in order to increase or decrease the trenchdepth until the desired depth or depth adjustment has been indicated bythe depth actuator encoder 382.

In a third method, the system 300 sends a command signal to the depthadjustment actuator 380 in order to increase or decrease the trenchdepth until the desired depth or depth adjustment has been indicated bya depth sensor 385 configured to measure the actual depth of the trench.In some embodiments, the depth sensor 385 may comprise a sensor (ormultiple sensors) disposed to measure a rotational position of the gaugewheel arms 260 relative to the row unit 200 as disclosed in Applicant'sProvisional Patent Application No. 61/718,073, the disclosure of whichis hereby incorporated herein in its entirety by reference. In otherembodiments, the depth sensor 385 comprises a sensor disposed todirectly measure the depth of the trench 38. One such embodiment isillustrated in FIG. 26, in which the depth sensor 385 includes a ski2610 configured to ride along the surface of the soil to the side of thetrench 38. In some embodiments, the ski 2610 includes twoground-engaging portions disposed to ride the surface of the soil oneither side of the trench 38. An arm 2620 is preferably mounted to anupper surface of a portion of the firmer 410 which engages the trench38. The arm 2620 preferably extends through an aperture in the ski 2610such that the arm slides vertically relative to the ski as the firmer410 deflects up and down. A magnet 2640 is preferably mounted to the arm2620. A Hall-effect sensor 2630 is preferably mounted to the ski 2610.The Hall-effect sensor 2630 preferably comprises a circuit boardincluding multiple Hall-effect sensors vertically spaced along a surfaceof the circuit board adjacent a plane defined by the range of motion ofthe magnet 2640. The Hall-effect sensor 2630 is preferably configured togenerate a signal related to the position of the magnet 2640. TheHall-effect sensor 2630 is preferably in electrical communication withthe monitor 50. The monitor 50 is preferably configured to determine thedepth of the trench 38 based on the signal generated by the Hall-effectsensor 2630, for example, using an empirical lookup table.

Depth Control Methods

The system 300 preferably controls the depth of the trench 38 in whichseeds are planted according to various processes based on one or moremeasurements or data inputs obtained by the system 300. It should beappreciated that the trench depth for an individual row unit 200 orgroup of row units may be controlled by measurements made by a sensor onthe row unit or by a sensor on another row unit or remote from the rowunits 200 (e.g., on a measurement unit 2500 as described herein) orremote from the implement 10 (e.g., on a base station 325 as describedherein). Likewise, the depth control methods described herein may beused to control the trench depth for a single row unit or a group of rowunits. Thus, for example, a single temperature measurement may be madeat a single row unit 200 and used to determine a desired depth atmultiple row units 200. Additionally, the moisture measurements used inthe processes described herein may be obtained either from one of themoisture sensors described herein or using multiple temperaturemeasurements at multiple depths, e.g., by generating a best-fit lineartemperature-depth relationship and consulting a lookup table orempirically-developed equation correlating the slope of thetemperature-depth relationship to soil moisture.

A process 500 for controlling trench depth based on soil moisture isillustrated in FIG. 5. At step 505, the system 300 preferably commandsthe depth adjustment actuator 380 to set the trench depth to a defaultdepth Dd, e.g., 1.75 inches. At step 510, the system 300 preferablymonitors the signal from a moisture sensor 350. At step 515, the system300 preferably compares the measured moisture M to a predeterminedrange, preferably defined by a low moisture Ml (e.g., 15%) and an highmoisture Mh (e.g., 35%). Moisture values are expressed herein as avolumetric percentage of water content; it should be appreciated thatother units or measures of soil moisture as are known in the art may besubstituted for these values. If the moisture M is less than Ml, then atstep 520 the system 300 preferably determines whether the current depthD is less than or equal to a maximum depth Dmax (e.g., 2.25 inches); ifit is, then at step 525 the system 300 preferably increases the depth Dby an increment (e.g., 0.175 inches) and again monitors the soilmoisture; if not, then at step 505 the system 300 preferably sets thedepth D to the default depth. If at step 515 the moisture M is greaterthan Mh, then at step 530 the system 300 preferably determines whetherthe current depth D is greater than or equal to a minimum depth Dmin(e.g., 1.25 inches); if it is, then at step 535 the system 300preferably decreases the depth D by an increment (e.g., 0.175 inches);if not, then at step 510 the system 300 preferably again monitors themoisture measurement signal. If at step 515 the current moisture M isbetween Ml and Mh, then at step 517 the system 300 preferably retainsthe current depth setting D and returns to monitoring the moisturemeasurement signal. In some embodiments of the method 500 reflected byalternate path 524, if M is greater than Mh and D is less than Dmin, thesystem adjusts the depth D to the default depth. In other embodiments ofthe method 500 reflected by alternate path 522, if M is less than Ml andD is greater than Dmax, then the system 300 returns to monitoring themoisture measurement signal without adjusting the depth D to the defaultdepth.

A process 600 for controlling trench depth based on soil temperature isillustrated in FIG. 6. At step 605, the system 300 preferably commandsthe depth adjustment actuator 380 to set the trench depth to a defaultdepth, e.g., 1.75 inches. At step 610, the system 300 preferablymonitors the signal from a temperature sensor 360. At step 615, thesystem 300 preferably compares the measured temperature T to apredetermined range, preferably defined by a low temperature Tl (e.g.,55 degrees Fahrenheit) and a high temperature Th (e.g., 65 degreesFahrenheit). If the temperature T is greater than Th, then at step 620the system 300 preferably determines whether the current depth D is lessthan or equal to a maximum depth Dmax (e.g., 2.25 inches); if it is,then at step 625 the system 300 preferably increases the depth D by anincrement (e.g., 0.175 inches) and again monitors the soil temperature;if not, then at step 605 the system 300 preferably sets the depth D tothe default depth. If at step 615 the temperature T is less than Tl,then at step 630 the system 300 preferably determines whether thecurrent depth D is greater than or equal to a minimum depth Dmin (e.g.,1.25 inches); if it is, then at step 635 the system 300 preferablydecreases the depth D by an increment (e.g., 0.175 inches); if not, thenat step 610 the system 300 preferably again monitors the moisturemeasurement signal. If at step 615 the current temperature T is betweenTl and Th, then at step 617 the system 300 preferably retains thecurrent depth D and returns to monitoring the temperature measurementsignal. In some embodiments of the process 600 reflected by alternatepath 622, if T is greater than Th and D is greater than Dmax, the system300 returns to monitoring the temperature measurement signal withoutadjusting the depth D to the default depth. In other embodiments of theprocess 600 reflected by alternate path 624, if T is less than Tl and Dis less than Dmin, then the system 300 adjusts the depth D to thedefault depth before returning to monitoring the moisture measurementsignal. In still other embodiments of the process 600 reflected byalternate path 626, if T is greater than Th and D is less than or equalto Dmax, then the system 300 returns to monitoring the temperaturemeasurement signal without adjusting the depth D to the default depth.

In other embodiments of the process 600, a stationary probe oron-planter temperature probe is configured and disposed to determine thesoil temperature at a constant depth (e.g., 4 inches) Dc greater than orequal to Dmax. The system preferably compares the measured temperatureat depth D to the measured temperature at Dc and determines adistribution of temperatures between D and Dc. The desired depth is thenselected corresponding to a desired temperature within the distribution.

A process 700 for controlling depth based on soil moisture and soiltemperature is illustrated in FIG. 7. At step 705, the system 300preferably runs the process 500 and the process 600 simultaneously. Theterm “simultaneously” as used herein means that the processes generallyrun at the same time and does not require that any particularcorresponding step in each process be carried out at or near the sametime; however, in a preferred embodiment, after each cycle of theprocesses 500, 600 (the term “cycle” meaning, e.g., a sequence resultingin a depth change recommendation even if the recommendation is to retainthe current depth) is completed, each process (e.g., process 500)preferably waits for the current cycle of the other process (e.g.,process 600) to complete before moving on to step 710. Once bothprocesses 500, 600 have generated a depth recommendation, at step 710the system 300 preferably determines whether one process is recommendinga depth change while the other process is recommending a depth change;if so, at step 715 the system 300 preferably follows the recommendationrequesting a depth change. If not, then at step 720 the system 300preferably determines whether the moisture process 500 is recommendingincreased depth while the temperature process 600 is requesting reduceddepth; if not, then at step 715 the system 300 preferably follows therecommendation requesting a depth change; if so, then at step 725 thesystem 300 preferably adjusts the trench depth up and down by incrementsrelative to the current depth setting (e.g., by 0.175 inches deeper andshallower than the current depth setting) in order to determine whethera threshold increase in moisture or temperature is obtained at depthsabove and below the current depth setting; after cycling up and down atstep 725, the system 300 preferably returns to the current depthsetting. At step 730, the system 300 preferably determines whethertemperature or moisture increases at the increased or reduced depthssampled at step 725. If temperature does not increase by at least athreshold (e.g., 2 degrees Fahrenheit) at decreased depth but moistureincreases by at least a threshold (e.g., 2%) at increased depth, then atstep 732 the system 300 preferably increases the depth by the incrementrecommended by the moisture process 500. If temperature increases by atleast a threshold (e.g., 2 degrees Fahrenheit) at decreased depth butmoisture does not increase by at least a threshold (e.g., 2%) atincreased depth, then at step 734 the system 300 preferably reduces thedepth by the increment recommended by the temperature process 600. Inall other cases, at step 736 the system 300 preferably retains thecurrent depth setting.

Another process 800 for controlling depth based on soil temperature andsoil moisture is illustrated in FIG. 8. At step 805, the systempreferably runs the process 500 and the process 600 simultaneously. Atstep 810, after each cycle of the processes 500, 600, the system 300preferably waits until both processes have supplied a depthrecommendation. At step 815, the system 300 preferably sums therecommended depth adjustment increments recommended by both processes500, 600; it should be appreciated that if either of the processes 500,600 recommend retaining the current depth, then that process contributeszero to the summed increment. At step 820, the system 300 preferablyadjusts the depth setting by the summed increment.

A modified process 800′ for controlling depth based on soil temperatureand soil moisture is illustrated in FIG. 9. The modified process 800′ issimilar to the process 800, but at step 812 multipliers are preferablyapplied to each of the incremental depth adjustments recommended by theprocesses 500, 600. In some embodiments, the multipliers may be based onthe relative agronomic cost associated with lost moisture and/ortemperature; for example, assuming a greater agronomic cost isassociated with lost moisture than with lost temperature, themultipliers may be 0.9 for the temperature recommendation and 1.1 forthe moisture recommendation. It should be appreciated that multipliersmay be applied to the input values rather than the resultingrecommendations of processes 500, 600; for example, a multiplier of 0.9per degree Fahrenheit may be applied to the temperature measurement anda multiplier of 1.1 per 1% moisture content may be applied to themoisture measurement.

A process 1100 for controlling depth based on soil data is illustratedin FIG. 11. At step 1105, the system 300 preferably accesses soil data(e.g., a geo-referenced soil data map such as a shape file associatingsoil data with geo-referenced positions); the monitor 50 may obtain thesoil data from the soil data server 345, although in some embodimentsthe soil data may be stored in the memory of the monitor 50. At step1110, the system 300 preferably compares a current location of theplanter 10 (e.g., as reported by the GPS receiver 52) to thegeo-referenced soil data in order to determine a soil characteristic(e.g., soil type) of the soil at the current location. At step 1115, thesystem 300 preferably determines a desired depth based on the retrievedsoil data, e.g., using a lookup table relating desired depths to soilcharacteristic ranges. In one illustrative example, the lookup table mayinclude a set of soil types, each associated with a desired depth; e.g.,Ipava soil may be associated with a desired depth of 1.75 inches whileSable soil may be associated with a desired depth of 1.8 inches. Inother embodiments, at step 1115 the system 300 uses a formula tocalculate a desired depth Dd based on the soil data, e.g., using theequation:D _(d)=1.75+0.007×(C−10)

Where: C is the clay content of the soil, expressed as a percentage.

At step 1120 the system 300 preferably adjusts the trench depth to thedesired depth.

A process 1200 for controlling depth based on soil data and soiltemperature is illustrated in FIG. 12. At step 1205, the system 300preferably accesses soil data as described above with respect to step1105 of process 1100. At step 1210, the system 300 preferably determinesa soil characteristic by comparing the current location to thegeo-referenced soil data as described above with respect to step 1110 ofprocess 1100. At step 1215, the system 300 preferably determines atemperature multiplier using a lookup table or equation relatingtemperature multipliers to soil characteristic ranges; e.g., amultiplier of 1.1 may be associated with Ipava soil while a multiplierof 0.9 may be associated with Sable soil. At step 1220, the system 300preferably determines the current temperature from the temperaturesensor signal. At step 1225, the system 300 preferably applies thetemperature multiplier to the measured temperature. At step 1230, thesystem 300 preferably determines a recommended depth adjustment usingthe modified (multiplier-applied) temperature, e.g., using the process600 described herein. At step 1235, the system 300 preferably appliesthe recommended depth adjustment. It should be appreciated that theprocess 1200 could be modified in order to control depth based on soiltype and other measured soil characteristics such as soil moisture. Insome embodiments, the monitor 50 consults a lookup table to determinevalues of Mh and Ml for the soil type corresponding to the currentposition of the row unit; e.g., the values of Mh, Ml may be 30%, 15%respectively for silt loam and 36%, 20% respectively for sandy clayloam.

A process 1300 for controlling depth based on weather data isillustrated in FIG. 13. At step 1305, the system 300 preferably accessesweather data, e.g. from the weather data server 340. The system 300 thendetermines a desired depth based on the weather data, which may include,inter alia, predicted precipitation, predicted air temperature, pastprecipitation, or past air temperature. In the illustrated example, atstep 1310 the system 300 obtains the predicted air temperature anddetermines the number of growing degree days G between the time ofplanting and the time of germination, e.g., using the equation below inwhich preferred values are specified for corn:

$G = {\sum\limits_{n = 1}^{N}\left( {\frac{T_{\max} + T_{\min}}{2} - {Tbase}} \right)}$

-   -   Where: N is the number of days between planting to germination,        e.g. 5;        -   Tmax is the maximum predicted temperature in Fahrenheit            during each successive 24-hour period following the time of            planting;        -   Tmin is the minimum predicted temperature in Fahrenheit            during each successive 24-hour period following the time of            planting, or Tbase if the minimum predicted temperature is            less than Tbase; and        -   Tbase is the base temperature for the seed, e.g., 50 degrees            Fahrenheit.

Once the number of predicted growing degree days is determined, at step1315 the system 300 preferably determines a desired depth based on thenumber of predicted growing days. In some embodiments, the system 300consults a lookup table stored in the memory of the monitor 50; forexample, a depth of 1.75 inches may be desired for growing degree daysgreater than 30, a depth of 1.5 inches may be desired for growing degreedays between 15 and 30, and a depth of 1.25 inches may be desired forgrowing degree days between 0 and 15 degrees. It should be appreciatedthat a shallower depth is generally desired for lesser growing degreeday values. At step 1335, the system 300 preferably adjusts the trenchdepth to the desired depth determined at step 1315.

A process 1400 for controlling depth based on weather data and soiltemperature is illustrated in FIG. 14. At step 1405, the system 300preferably accesses weather data as described above with respect toprocess 1300. At step 1410, the system 300 preferably determines anumber of growing degree days as described above with respect to process1300. At step 1415, the system 300 preferably determines the currenttemperature based on the signal received from the temperature sensor360. At step 1420, the system 300 preferably applies a multiplier to themeasured temperature; the multiplier is preferably based on the numberof growing degree days calculated at step 1410. For example, amultiplier of 1 may be applied for growing degree days greater than 15and a multiplier of 0.8 may be applied for growing degree days less than15; it should be appreciated that resulting modified soil temperature ispreferably smaller for smaller growing degree day values. At step 1425,the system 300 preferably determines a recommended depth adjustmentbased on the modified (multiplier-applied) temperature, e.g., using theprocess 600 described herein. At step 1430, the system 300 preferablyadjusts the trench depth according to the adjustment determined at step1425.

A process 1500 for controlling depth based on data received from thebase station 325 is illustrated in FIG. 15. At step 1505, the system 300preferably receives temperature measurements at multiple depths from thebase station 325. At step 1510, the system 300 preferably determines anempirical relationship between depth and temperature, e.g., bydetermining a linear or other equation that best fits the temperaturemeasurements at the base station 325. At step 1515, the system 300preferably receives moisture measurements at multiple depths from thebase station 325. At step 1520, the system 300 preferably determines anempirical relationship between depth and moisture, e.g., by determininga linear or other equation that best fits the moisture measurements atthe base station 325. At step 1525, the system 300 preferably determinesa desired depth based on the moisture and depth measurements receivedfrom the base station 325. In some embodiments, the system 300 selects adepth at which the loss L resulting from a lack of moisture andtemperature is minimized, e.g., where the loss L is determined by theequation:L=L _(m) +L _(t)

Where: Lt=Tl−T for T<Tl, Lt=0 for T≥Tl;

-   -   Lm=15−Ml for M<Ml, Lm=0 for M≥Ml;    -   Ml is the minimum moisture level as described elsewhere herein,        e.g., 15%; and    -   Tl is the minimum temperature described elsewhere herein, e.g.,        50 degrees F.

The system 300 preferably selects a depth corresponding to the minimumL-value for all depths between the maximum depth Dmax and minimum depthDmin. If the minimum value of L is within a threshold (e.g., 5%) of themaximum L-value, then the system 300 preferably selects a default depth(e.g., 1.75 inches) instead of the depth corresponding to the minimumL-value. At step 1530, the system 300 preferably adjusts the trenchdepth to the depth selected at step 1525.

A process 1600 for controlling depth based on soil and moisture data andweather data is illustrated in FIG. 16. At step 1605, the system 300preferably receives temperature measurements at multiple depths from thebase station 325 as described above with respect to the process 1500. Atstep 1610, the system 300 preferably determines an empiricalrelationship between temperature and depth as described above withrespect to the process 1500. At step 1615, the system 300 preferablyreceives moisture measurements at multiple depths from the base station325 as described above with respect to the process 1500. At step 1620,the system 300 preferably determines an empirical relationship betweenmoisture and depth as described above with respect to the process 1500.At step 1625, the system 300 receives temperature data, preferably fromthe base station 325 and/or the weather data server 340. The temperaturedata may include past recorded air temperature (e.g., recorded local airtemperature during the previous 24 hours) as well as forecasted airtemperature (e.g., forecasted local air temperature during the following60 hours); the temperature data may also include recorded cloudconditions and forecasted cloud conditions. At step 1630, the system 300preferably adjusts the temperature-depth relationship based on thetemperature data. For example, in some embodiments the system 300 mayadjust the temperature-depth relationship based on the local airtemperature recorded during a period prior to planting and theforecasted temperature during the germination period (e.g., 60 hours)after planting. In one such embodiment, the system 300 modifies thetemperature-depth relationship T(d) to a modified temperature-depthrelationship T′(d) using the equation:

${T^{\prime}(d)} = {{T(d)} \times \frac{H_{p}}{H_{f}} \times \frac{\int_{0}^{H_{f}}{{A(h)}{dh}}}{\int_{- {Hp}}^{0}{{A(h)}{dh}}}}$

-   -   Where: A(h) is air temperature as a function of time in hours h;        -   Hp is the number of hours prior to planting over which            recorded air temperature is used; and        -   Hf is the number of hours after planting over which            forecasted air temperature is used.

Continuing to refer to process 1600 of FIG. 16, at step 1635 the system300 receives precipitation data, preferably from the base station 325and/or the weather data server 340. The precipitation data may includepast recorded rainfall (e.g., recorded local rainfall during theprevious 24 hours) as well as forecasted rainfall (e.g., forecastedlocal rainfall during the following 60 hours). At step 1640, the system300 preferably adjusts the moisture-depth relationship based on theprecipitation data. For example, in some embodiments the system 300 mayadjust the moisture-depth relationship based on local rainfall recordedduring a period prior to planting and the forecasted rainfall during thegermination period (e.g., 60 hours) after planting. In one suchembodiment, the system 300 modifies the moisture-depth relationship M(d)to a modified moisture-depth relationship M′(d) using the equation:

${M^{\prime}(d)} = {{M(d)} \times \frac{H_{p}}{H_{f}} \times \frac{\int_{0}^{H_{f}}{{R(h)}{dh}}}{\int_{- {Hp}}^{0}{{R(h)}{dh}}}}$

-   -   Where: R(h) is rainfall as a function of time in hours h;        -   Hp is the number of hours prior to planting over which            recorded rainfall is used; and        -   Hf is the number of hours after planting over which            forecasted rainfall is used.

Continuing to refer to process 1600 of FIG. 16, at step 1645 the system300 preferably determines a desired depth based on the modifiedtemperature-depth and modified moisture-depth relationships generated atsteps 1630, 1640; in some embodiments, step 1645 is carried out asdescribed herein with respect to step 1525 of process 1500. At step1650, the system 300 preferably adjusts the trench depth to the desireddepth.

Display and User Interface

As illustrated in FIG. 17, the monitor 50 is preferably configured todisplay a screen 1700 displaying spatial soil temperature data. Thescreen 1700 preferably displays the live position of the planter 10 andeach of the associated row units 200 (numbered 1 through 4 in FIG. 17).In the embodiment of FIG. 17, temperature measurements are made at eachrow unit 200. Each temperature measurement is preferably time-stampedand associated with a GPS position; the screen 1700 preferably displaysresulting temperature-location data points 1722, 1724, 1726 associated(e.g., by color or hatching) with legend ranges 1712, 1714, 1716, whichare preferably illustrated in a legend 1710. An interface 90 preferablyenables the user to navigate between map screens.

As illustrated in FIG. 18, the monitor 50 is preferably configured todisplay a screen 1800 displaying spatial soil moisture data. The screen1800 preferably displays the live position of the planter 10 and each ofthe associated row units 200 (numbered 1 through 4 in FIG. 18). In theembodiment of FIG. 18, moisture measurements are made at each row unit200. Each moisture measurement is preferably time-stamped and associatedwith a GPS position; the screen 1800 preferably displays resultingmoisture-location data points 1822, 1824, 1826 associated with legendranges 1812, 1814, 1816, which are preferably illustrated in a legend1810.

As illustrated in FIG. 19, the monitor 50 is preferably configured todisplay a screen 1900 displaying spatial trench depth data. The screen1900 preferably displays the live position of the planter 10 and each ofthe associated row units 200 (numbered 1 through 4 in FIG. 19). In theembodiment of FIG. 19, trench depth measurements (or records ofcommanded trench depth) are made at each row unit 200. Each trench depthmeasurement is preferably time-stamped and associated with a GPSposition; the screen 1900 preferably displays resulting depth-locationdata points 1922, 1924, 1926 associated with legend ranges 1912, 1914,1916, which are preferably illustrated in a legend 1910.

In some embodiments, the screens 1700, 1800 and/or 1900 include a mapoverlay comprising spatial data from prior operations and/or priorseasons. The map overlay may be compared side-by-side with or partiallytransparent and superimposed over the temperature, moisture or depthdata. In some embodiments the map overlay comprises aerial imagery(e.g., photographic, NDVI, plant emergence, or thermal imagery)previously captured for the same field. In other embodiments, the mapoverlay comprises application data (e.g., planting data gathered fromseed sensors or nitrogen application rate data). In still otherembodiments the map overlay comprises yield data recorded during harvestin a prior season.

Turning to FIG. 20, the monitor 50 is preferably configured to display agermination summary screen 2000. A window 2005 preferably displays thepercentage of seeds S planted at a desired moisture level, which themonitor 50 preferably calculates according to the equation:

$S = {\frac{S_{m}}{S_{t}} \times 100\%}$

-   -   Where: St is the total number of seeds planted during the        current planting operation (e.g., in the current field); and        -   Sm is the number of seeds planted within a threshold            distance (e.g., 6 inches) of a GPS location associated with            a moisture measurement of at least a threshold value (e.g.,            15%).

In embodiments of the system 300 having a moisture sensor 350 at eachrow, the value of Sm is preferably determined on a row-by-row basis andthen summed. In embodiments having fewer moisture sensors 350 than rowunits 200, each moisture sensor is associated with one or more row unitsand the value of Sm is determined on a row-by-row basis with each rowunit using the moisture measurements of its associated moisture sensor.The monitor 50 also determines the value of S for each individual rowand identifies the row having the lowest value of S in window 2005.

The germination summary screen 2000 also preferably includes a window2010 displaying the percentage of seeds R planted at a desiredtemperature, which the monitor 50 preferably calculates according to theequation:

$R = {\frac{R_{t}}{S_{t}} \times 100\%}$

-   -   Where: Rt is the number of seeds planted within a threshold        distance (e.g., 6 inches) of a GPS location associated with a        temperature measurement of at least a threshold value (e.g., 55        degrees Fahrenheit).

In embodiments of the system 300 having a temperature sensor 360 at eachrow, the value of Rm is preferably determined on a row-by-row basis andthen summed. In embodiments having fewer temperature sensors 360 thanrow units 200, each temperature sensor is associated with one or morerow units and the value of Rm is determined on a row-by-row basis witheach row unit using the temperature measurements of its associatedtemperature sensor. The monitor 50 also determines the value of R foreach individual row and identifies the row having the lowest value of Rin window 2010.

The screen 2000 also preferably includes a window 2015 displaying anestimate of the probability P of successful germination of seeds plantedduring the current planting operation (e.g., in the current field),which the monitor 50 preferably calculates using the equation:

$P = {\frac{R_{t} + S_{m}}{2S_{t}} \times 100\%}$

In embodiments of the system 300 having moisture sensors but notemperature sensors, the monitor 50 preferably calculates thegermination probability P using the equation:

$P = {\frac{S_{m}}{S_{t}} \times 100\%}$

In embodiments of the system 300 having moisture sensors but notemperature sensors, the monitor 50 preferably calculates thegermination probability P using the equation:

$P = {\frac{R_{t}}{S_{t}} \times 100\%}$

Continuing to refer to FIG. 20, the screen 2000 preferably includes awindow 2020 displaying the average of the current moisture measurementsobtained from the moisture sensors 350. The window 2020 preferablyidentifies the row unit or section (i.e., group of row units associatedwith a single moisture sensor 350) from which the lowest moisturemeasurement is obtained. The screen 2000 preferably includes a window2025 displaying the average of the current temperature measurementsobtained from the temperature sensors 360. The window 2025 preferablyidentifies the row unit or section (i.e., group of row units associatedwith a single temperature sensor 360) from which the lowest temperaturemeasurement is obtained. The screen 2000 also preferably includes awindow 2030 displaying the current average depth setting commanded tothe depth adjustment actuators 380 (or in some embodiments, the currentaverage actual depth measurement obtained from depth sensors 385). Thewindow 2030 also preferably identifies the row units having theshallowest and deepest trench depths. The screen 2000 also preferablyincludes an interface 2040 enabling the user to navigate to row detailscreens described later herein.

Continuing to refer to FIG. 20, the screen 2000 preferably includes aplanting recommendation window 2035 displaying a recommendationindicating whether planting is recommended (e.g., “Keep Planting”) ornot recommended (e.g., “Stop Planting”). The monitor 50 preferablydetermines which recommendation to display based on current moistureand/or temperature measurements made by the system 300 or the averagemeasurements made during the current planting operation (e.g., in thecurrent field). In some embodiments the monitor recommends planting onlyif the loss L (calculated as described above) is less than a threshold,e.g., 20. In embodiments in which the system 300 includes moisturesensors 350 but no temperature sensors 360, the monitor 50 preferablyrecommends planting only if the moisture measurement displayed in window2020 is greater than a threshold, e.g., 15%. In embodiments in which thesystem 300 includes temperature sensors 360 but no moisture sensors 350,the monitor 50 preferably recommends planting only if the temperaturemeasurement displayed in window 2025 is greater than a threshold, e.g.,55 degrees Fahrenheit.

It should be appreciated that the moisture and temperature valuesdisplayed in the screen 2000 and used to calculate the germinationpotential value (window 2015) and determine the planting recommendation(window 2035) may be adjusted based on weather data as described earlierherein.

Turning to FIG. 21, the monitor 50 is preferably configured to display arow by row summary screen 2100. The screen 2100 preferably includes agraph 2110 illustrating the trench depth at each row unit, a graph 2130illustrating the moisture measured at each row unit, a graph 2120illustrating the germination potential determined for each row unit, anda graph 2140 illustrating the temperature measured at each row unit.

Turning to FIG. 22, the monitor 50 is preferably configured to display arow details screen 2200 for each row unit 200. The row details screenpreferably includes windows 2205, 2210, 2215, 2220, 2225, 2230displaying individual row values used to calculate the average valuesdisplayed in windows 2005, 2010, 2015, 2020, 2025, 2030, respectively,of the screen 2000.

Turning to FIG. 23, the monitor 50 is preferably configured to display asetup screen 2300 enabling the user to vary the parameters used in thedepth control processes described herein. The screen 2300 preferablyincludes a depth interface 2310 for setting the minimum depth Dmin, thedefault depth Dd, and the maximum depth Dmax. The screen 2300 preferablyincludes a temperature interface 2320 for setting the high temperatureTh and the low temperature Tl. The screen 2300 preferably includes amoisture interface 2330 for setting a high moisture Mh and a lowmoisture Ml. The screen 2300 preferably includes an interface 2340enabling the user to select which variables are used to control depth.The monitor 50 is preferably configured to select a depth controlprocess which uses the variables selected by the user as in puts anddoes not require the variables not selected by the user. For example, ifthe user selects only “Live Moisture”, the system 300 preferably usesthe process 500 to control trench depth, whereas if the user selectsonly “Live Moisture” and “Live Temperature”, the system 300 preferablyuses one of the processes 700, 800, or 800′ to control trench depth.

Continuing to refer to FIG. 23, the screen 2300 preferably includes adepth control interface 2350 enabling allowing the user to turn off allof the depth control processes (e.g., by selecting “Off”) such that thesystem 300 leaves the trench depth at each row unit 200 at the currentsetting (or in some embodiments, returns each row unit to the defaultdepth Dd). The screen 2300 also preferably includes a user approvalinterface 2360 enabling the user to select whether the monitor 50requests user approval before requesting. If the user selects “On” inthe interface 2360, then the monitor 50 preferably prompts the user toapprove or reject changes in depth requested by the depth controlprocesses described herein (e.g., by a window superimposed over theactive screen).

Turning to FIG. 27, the monitor 50 is preferably configured to display ascreen 2700 for manually setting trench depth and preferably for viewingmoisture and temperature data. The screen 2700 preferably displays agraph 2710 illustrating the relationship between depth and moisture andbetween depth and temperature. The depth-temperature relationshipillustrated in the graph 2710 is preferably generated by averaging thetemperature measurements made by the system 300 at various depths. Thedepth-moisture relationship illustrated in the graph 2720 is preferablygenerated by averaging the moisture measurements made by the system 300at various depths. It should be appreciated that the graph 2620 assiststhe user in selecting a depth at which the desired moisture andtemperature are available. The screen 2700 preferably displays a depthinterface (e.g., a sliding interface as illustrated) allowing the userto set a trench depth; the system 300 preferably adjusts the trenchdepth at each row unit to the manually selected trench depth if a manualoverride interface 2605 is set to “On”.

The foregoing description is presented to enable one of ordinary skillin the art to make and use the invention and is provided in the contextof a patent application and its requirements. Various modifications tothe preferred embodiment of the apparatus, and the general principlesand features of the system and methods described herein will be readilyapparent to those of skill in the art. Thus, the present invention isnot to be limited to the embodiments of the apparatus, system andmethods described above and illustrated in the drawing figures, but isto be accorded the widest scope consistent with the spirit and scope ofthe appended claims.

The invention claimed is:
 1. A method of monitoring and displayingsensed soil moisture as an agricultural machine traverses a fieldapplying an agricultural input, the method comprising: with a soilmoisture sensor disposed on the agricultural machine sensing soilmoisture at a predetermined soil depth as the agricultural machinetraverses the field; visually displaying to an operator of theagricultural machine a representation of the sensed soil moisture as theagricultural machine traverses the field; as the agricultural machinetraverses the field, determining a percentage of the agricultural inputapplied by the agricultural machine at a depth where the sensed soilmoisture is at a desired moisture level.
 2. The method of claim 1,wherein the representation of soil moisture comprises soil moisture aspercent content of soil.
 3. The method of claim 1, wherein therepresentation of soil moisture comprises a soil moisture range of thesensed soil moisture.
 4. The method of claim 1, wherein the agriculturalmachine comprises a seed firmer and wherein the soil moisture sensor ismounted on the seed firmer.
 5. The method of claim 1, wherein the soilmoisture sensor is mounted on the agricultural machine to measuremoisture at or proximate a bottom of a seed trench formed using theagricultural machine.
 6. The method of claim 1, wherein the soilmoisture sensor is mounted on the agricultural machine to measuremoisture a soil cutting depth.
 7. The method of claim 6, furthercomprising: automatically controlling the soil cutting depth based onthe sensed soil moisture.
 8. The method of claim 1, further comprisingcontrolling the depth of the agricultural input applied by theagricultural machine based on the sensed soil moisture.
 9. The method ofclaim 1, further comprising: automatically controlling a rate ofapplication of the agricultural input based on the soil moisture data,the agricultural input being at least one agricultural input selectedfrom the set consisting of pesticides, fertilizers, growth regulators,defoliants, and seeds.
 10. The method of claim 1, wherein theagricultural machine is a planter having a plurality of row units, andwherein the agricultural input is seed, with each of the plurality ofrow units planting a seed row, and further comprising: visuallydisplaying to the operator a percentage of the seed planted at thedesired moisture level.
 11. The method of claim 10, further comprising:(a) determining a first value (Sm) by identifying a number of seedsplanted within a predetermined threshold distance of a threshold soilmoisture value; (b) determining a second value (St) by identifying atotal number of seeds planted during a defined period of operation ofthe planter; (c) calculating a quotient value (S) by dividing the firstvalue Sm by the second value St; and (d) calculating a percentage of theseed planted at the desired moisture level by multiplying the quotient Sby 100%.
 12. The method of claim 11, wherein each of the plurality ofrow units includes the soil moisture sensor, and wherein the first valueSm is determined on a row-by-row basis of the agricultural planter. 13.The method of claim 12, further comprising: identifying which seed rowplanted by each of the plurality of row units has a lowest quotientvalue S and visually displaying the lowest quotient value S to theoperator.
 14. The method of claim 11, further comprising: (e)calculating a germination probability value (P) by dividing the firstvalue Sm by the second value St to determine a germination probabilityquotient and multiplying the germination probability quotient by 100%.